What Are Poly Bushings And Do You Need Them

Read on to discover the practicality, history, applications, and necessity of poly bushings, as well as other bushings.

Poly bushings are one of a few kinds of bushings, which are suspensions in the car's engine that help to keep operations flowing smoothly and absorb impact. Bushings can often be located in areas of movement in the chassis and suspension system.

Bushings became commonplace in the 1930s when their usefulness, longevity, practicality, and lack of deterioration made them an ideal choice for civilian vehicles. Prior to that, their main use was in the military. In most cases, poly bushes end up outlasting the vehicle they service, though this could change if the driver is particularly unskilled or is rough while operating the vehicle.

Read on to discover the practicality, history, applications, and necessity of poly bushings, as well as other bushings.

Related: Hoonigan's Donk Project Gets A Carbon Layer And Hockey Puck Bushings

The term "poly bushings" is short for "polyurethane bushings."

They have a specific function within the engine. Basically, any kind of bushings are intended to reduce metal-on-metal friction within the engine, making the engine feel tighter, more responsive, smoother, and resistant to bumps, shocks, and potholes. These bushings are suspensions that don't have to be made from a designated material, but "poly bushings" are the ones made out of polyurethane, as the name implies.

Poly bushings help keep the ride smooth, and when the car shakes or is overly responsive to shocks and impact, then these could be a prime candidate as to why the car reacted in that manner. These simple parts play a significant role in both engine operation and driver's riding experience.

Bushings have two parts: there's a cushioned interior that almost feels like a sponge, and there's an outer sleeve that is usually made of metal. The lifespan of these bushes varies from car to car, depending on the driver, their driving style, and what type of environment these cars were driven in.

A few symptoms indicative of replacement are fender-based creaking or banging, frame rattling while driving over harsh terrain, severe lack of control while steering, looseness in steering, massive road noise, and intense vehicle vibration.

This particular kind of suspension is good for handling. Shock absorbers improve a car's handling, and suspension helps bear the impact of any shocks, such as potholes, bumps, and cracks in the road. The suspension is at its most vulnerable where the parts link together, and that's where the polyurethane aspect comes in.

Poly bushings have been tested on several cars, both on city streets as well as race tracks. Most cars manufactured these days are made for civilians in the general public, so comfort and cost are both essential. Polyurethane is a solid material to choose from when resisting any cuts, tears, and abrasions. Further, it is more oil-resistant and chemical-resistant than bushings made from other types of material, boosting its longevity.

Having polyurethane fill the connective gaps helps ensure that the linking points and joints have less freedom to move around and fall apart, keeping them stiff with less cushion for both impact and torsion. They provide a better feel for the car and driver, they have longevity and durability on their side, and they offer more control while the car is moving. The stiffness of polyurethane means less chance of unwanted movement in the chassis and suspension, leading to a renewed sense of order and precision while operating the vehicle.

Related: 2020 Chevrolet Suburban Spotted With Major Suspension Update

A lot of bushings don't have to be made of polyurethane; rubber is another substance commonly used for bushings. Both substances have their advantages, and naturally, there will be occasions where rubber would be preferred. It's actually the standard type of bushing for most vehicles.

Rubber is softer than polyurethane, so it can ward off noise and vibrations better to guarantee a smoother experience. It's often more pliable and softer than polyurethane, though their lifespan is shorter because they are more susceptible to wear and tear, as well as to exposure from chemicals.

Road stresses also are likely to make rubber malformed and stretched out beyond its original shape. These bushings are also more likely to need replacement while the vehicle is still operational, unlike their polyurethane counterparts that outlast the vehicles they service.

Rubber will also be more sensitive, so every bump and pothole will be prominently pronounced. Further, engines heat up, and rubber is also susceptible to heat. One benefit of rubber, though, is that they never squeak because the bushings are bonded to their shells and are unable to move.

A few of the features in bushings are common enough to help define them. Polyurethane bushings are mainly an aftermarket product, because, as mentioned before, most cars come standard with rubber bushings already installed. Performance, durability, and comfort are three key factors that determine which type of bushings would be most effective and practical.

Rubber is quieter but not as efficient, while polyurethane is louder but increasingly more efficient. Which type of suspension is used in a vehicle is ultimately determined by the vehicle's purpose, and that's a decision every individual driver will need to make for themselves.

Sources: dsportmag.com, poly-tek.com, suspension.com,

Next: Body Lift Vs Suspension Lift: Here's How To Decide Which Is Right For You

Kenny graduated with a Bachelor of Science in Communication from the University of Indianapolis. He has since gone on to be a reporter for and write for three newspapers following graduation. Kenny also has experience editing websites using WordPress, and he directed a newspaper team to produce two issues during Indianapolis' 2012 Super Bowl. Kenny was hired onto Valnet to write list articles in March 2020. In his free time, Kenny is often out socializing with friends, practicing karate, reading comics, discussing the Enneagram, or at a game night.